Techland, developer of the highly anticipated Dead Island zombie game, seems to have made a rather large mistake with the PC version of the game. Dead Island is now available to purchase and download on Steam for U.S. gamers, but the build you get to play is clearly not what Techland or publisher Deep Silver intended.

The Steam forums are filling up with complaints about this being an internal development build, unoptimized, ported code from the Xbox 360 version, and with access to developer only options such as turning on all the cheats, getting rid of logos, and developer keys. In other words, if you know how, you can run through walls, be immune to damage, and treat the game like a giant sandbox if you so wish.

Techland is investigating the issue, but it looks like someone mistakenly uploaded the wrong build to Steam’s severs and nobody bothered to check it worked or was correct. Now, hundreds, if not thousands of PC gamers have the wrong copy of the game on their machines.

As it’s Steam, I can’t see this being hard to fix. However, gamers may be a little upset if they end up having to re-download the entire game the next time an update is released, but at least then you won’t be playing a poor Xbox 360 port.

There’s no official word yet on exactly what happened from Techland or Deep Silver, but I’m sure they’ll release a statement before the end of the day, and hopefully the correct version to Steam as soon as pssoble.